[core] plugins: Move validateNodeDesc from __init__.py to plugins.py

The validation of the node descriptions will be handled directly within
the `NodePlugin` objects and there is thus no need for this method to
exist outside of plugins.py.

meshroom/core/plugins.py

@@ -8,6 +8,40 @@ from pathlib import Path
 from meshroom.common import BaseObject
 from meshroom.core import desc
 
+def validateNodeDesc(nodeDesc: desc.Node) -> list:
+    """
+    Check that the node has a valid description before being loaded. For the description
+    to be valid, the default value of every parameter needs to correspond to the type
+    of the parameter.
+    An empty returned list means that every parameter is valid, and so is the node's description.
+    If it is not valid, the returned list contains the names of the invalid parameters. In case
+    of nested parameters (parameters in groups or lists, for example), the name of the parameter
+    follows the name of the parent attributes. For example, if the attribute "x", contained in group
+    "group", is invalid, then it will be added to the list as "group:x".
+
+    Args:
+        nodeDesc: description of the node.
+
+    Returns:
+        errors: the list of invalid parameters if there are any, empty list otherwise
+    """
+    errors = []
+
+    for param in nodeDesc.inputs:
+        err = param.checkValueTypes()
+        if err:
+            errors.append(err)
+
+    for param in nodeDesc.outputs:
+        if param.value is None:
+            continue
+        err = param.checkValueTypes()
+        if err:
+            errors.append(err)
+
+    return errors
+
+
 class ProcessEnv(BaseObject):
     """
     Describes the environment required by a node's process.